Counter torque tube connection

ABSTRACT

A counter torque tube connection which couples a first tube and a second tube in turbine engine. The connection first tube includes a male connector component having a ballnose. The ballnose includes a plurality of protrusions. The connection second tube includes a female connector component having a ferrule end fitting sized to receive the ballnose. The female connection component includes a plurality of protrusions that interfit with the ballnose protrusions. The tubes are coupled by extended a nut over the female component and coupling the nut to the male component. The interfitting protrusions prevent torsional loads applied to the tubes from being transmitted to the nut so that the nut remains secured.

FIELD OF THE INVENTION

This invention relates generally to turbine engines and, moreparticularly, to an apparatus for preventing torsional loads fromloosening tubing connections.

BACKGROUND OF THE INVENTION

Turbomachinery frequently employs a wide variety of tubing to routedifferent types of fluids throughout the machinery. The tubing commonlycomprises male and female body components joined by a nut coupled to oneof the components cooperating with threads on the other component. Thiscoupling permits connection and disconnection by relative rotation aboutthe tubing centerline. The conditions to which the connected coupling issubjected can sometimes, over a period of time, cause loosening of thenut and resultant leakage. For example, a typical tubing connection of agas turbine engine is subjected to various vibratory and torsionalloads, as well as significant thermal growth.

Many different types of lock devices have been previously proposed andimplemented to prevent the loosening of such couplings. However, thesedevices have generally suffered from one or more disadvantages ordefects. For example, certain lock designs require installation prior tocoupling makeup, and retrofitting is not possible without systemdisassembly. With certain other designs, it has been necessary to locatethe coupling components in a particular aligned relationship before thedevices will function properly.

It would be desirable, to provide an apparatus which facilitatescoupling of the male and female components while eliminating theloosening loads on the nut due to the loads placed on the coupling. Itwould also be desirable to provide such an apparatus which is allows thetubing to be coupled without system disassembly.

SUMMARY OF THE INVENTION

These and other objects may be attained by a counter torque tubeconnection which, in one embodiment, couples a first tube to a secondtube, in a turbine engine. The connection includes a first tube having amale connector component at one end. The male connector componentincludes a ballnose having a plurality of outward extending radialprotrusions. The connection also includes a second tube having a femaleconnector component at one end. The female component includes a ferruleend fitting having a plurality of inward extending radial protrusionssized to receive and interfit with the male component protrusions. Theconnection further includes a nut that secures the first and secondtubes.

The first and second tubes are coupled by extending the male connectorcomponent protrusions into the ferrule end fitting protrusions. The nutis then extended over the female connector component and secured to themale connector component. After securing the first and second tubesusing the connection, torsional loads are prevented from being appliedto the nut by the first and second protrusions.

The above-described counter torque tube connection couples a first tubeto a second tube, in a gas turbine engine. In addition, the connectionprevents torsional loads from being transmitted to the nut so that thenut remains secured. Additionally, the connection allows the tubes to becoupled without disassembly of the engine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a counter torque tube connection.

FIG. 2 is a cross sectional view of counter torque tube connection ofFIG. 1 accordance with one embodiment of the present invention.

FIG. 3 is a partial cross-sectional cut-away view of counter torque tubeconnection of FIG. 1.

FIG. 4 is a cross sectional view of the counter torque tube connectionin accordance, with an alternative embodiment.

FIG. 5 is a cross sectional view of the counter torque tube connectionin accordance with another alternative embodiment.

DETAILED DESCRIPTION

FIG. 1 is a side view of a counter torque tube connection 10 including afirst tube 14 and a second tube 18. First tube 14 includes a first end(not shown), a second end 22, and a flow passage (not shown). Secondtube 18 includes a first end 26, a second end (not shown), and a flowpassage (not shown). Connection 10 also includes a substantiallycylindrical shaped nut 30 sized to extend over second tube first end 26and to receive first tube second end 22 so that first and second tubes14 and 18 are coupled.

As shown in FIG. 2, first tube first end 22 includes a substantiallycylindrical shaped male connector component 34 having a ballnose 38 anda threaded outer diameter 42. Ballnose 38 includes a plurality of axialprotrusions 46 extending radially outward. Second tube first end 26includes a substantially cylindrical shaped female connector component50 having a ferrule end fitting 54 sized to receive ballnose 38. Ferruleend fitting 54 includes a plurality of axial protrusions 58 extendingradially inward. Protrusions 46 are sized and spaced to interfit withprotrusions 58. Substantially cylindrical shaped nut 30 includes a tubebore 62 sized to receive second tube 18 and a coupling bore 66 sized toreceive male connector component 34. Coupling bore 66 is threaded andsized to threadedly engage male connector component threads 42. As shownin FIG. 3, protrusions 46 and 58 are involute splines for limitingtorque load transmitted through first and second tubes 14 and 18. Thecomponents of connection 10 may, for example, be fabricated from A286stainless steel. The specific material selected depends, of course, onthe specific temperature requirements and design parameters of aspecific application, and materials other than A286 stainless steel canbe used, e.g., Inconel.

To secure first tube 14 to second tube 18 using connection 10, ballnose38 is extended into ferrule end fitting 54 and nut 30 couples first andsecond tubes 14 and 18. Particularly, ballnose spline shaped protrusions46 are aligned with ferrule protrusions 58 and ballnose 38 is extendedinto ferrule 54. Nut 30 is then extended over male component 34 andthreadedly engaged to outer diameter threads 42. First and second tubes14 and 18 are coupled by securing nut 30. Securing nut 30 plasticallydeforms ferrule end fitting 54 and balinose 38 so that fluid leakage isprevented. In operation, spline protrusions prevent torsional loadsapplied first or second tubes 14 and 18 from being transmitted to nut 30so that the nut 30 remains secure.

In an alternative embodiment of the present invention shown in FIG. 4,ballnose protrusions 100 form a hexagonal shape 104 and ferrule endfitting protrusions 108 form a hexagonal opening 112. Hexagonal opening112 is sized to receive hexagonal shape 104 when ballnose 38 is extendedinto ferrule end fitting 54. In another embodiment of the inventionshown in FIG. 5, ballnose protrusions 200 form a square shape 204 andferrule end fitting protrusions 208 form a square opening 212. Opening212 is sized to receive shape 204 when ballnose 38 is extended intoferrule end fitting 54.

The above-described counter torque tube connection allows a first tubeto be couple tube while preventing loads from loosening the connectionand causing leakage. In addition, the connection allows the tubes to beconnected without disassembly of the tubes.

From the preceding description of various embodiments of the presentinvention, it is evident that the objects of the invention are attained.Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is intended by way ofillustration and example only and is not to be taken by way oflimitation. Accordingly, the spirit and scope of the invention are to belimited only by the terms of the appended claims.

What is claimed is:
 1. A counter torque tube connection for use in aturbine engine, said connection comprising:a first tube comprising aflow passage, a first end, and a second end, said first end having aballnose connection, said ballnose connection having an outer diameterwherein at least a portion of said outer diameter is threaded, and atleast one axial protrusion extending radially outward; a second tubecomprising a flow passage, a first end, and a second end, said first endhaving a ferrule end fitting, said ferrule end fitting comprising aninner surface and a smooth outer surface and configured to receive saidballnose connection, said ballnose connection and said ferrule endfitting further comprising a plurality of interfitting protrusions; anda nut coupled to said second tube configured to secure said first tubeto said second tube.
 2. A counter torque tube connection in accordancewith claim 1 wherein said nut is threaded and wherein said nutthreadedly engages said ballnose connection threads.
 3. A counter torquetube connection in accordance with claim 1 wherein said ferrule endfitting has at least one axial protrusion extending radially inward fromsaid inner surface.
 4. A counter torque tube connection in accordancewith claim 3 wherein said ballnose and ferrule end fitting protrusionsare involute splines.
 5. A counter torque tube connection in accordancewith claim 3 wherein said ballnose protrusions extend away from saidfirst tube and form a hexagonal shape and said ferrule end fittingprotrusions form a hexagonal opening for receiving said ballnoseprotrusion hexagonal shape.
 6. A counter torque tube connection inaccordance with claim 3 wherein said ballnose protrusions extend awayfrom said first tube and form a square shape and said ferrule endfitting protrusions form a square opening for receiving said ballnoseprotrusion square shape.
 7. A counter torque connector apparatus forcoupling a first tube to a second tube, said apparatus comprising:a maleconnector component comprising a flow passage, a first end, and a secondend, said first end having a ballnose connection, said ballnoseconnection having an outer diameter wherein at least a portion of saidouter diameter is threaded, and at least one axial protrusion extendingradially outward, said second end coupled to the first tube; a femaleconnector component comprising a flow passage, a first end, and a secondend, said first end having a ferrule end fitting, said ferrule endfitting comprising an inner surface and a smooth outer surface andconfigured to receive said ballnose connection, said ballnose connectionand said ferrule end fitting further comprising a plurality ofinterfittinq protrusions, said second end coupled to the second tube;and a nut coupled to said male connector configured to secure said maleconnector to said female connector.
 8. A counter torque connectorapparatus in accordance with claim 7 wherein said nut is threaded andwherein said nut threadedly engages said ballnose connection threads. 9.A counter torque connector apparatus in accordance with claim 7 whereinsaid ferrule end fitting has at least one axial protrusion extendingradially inward from said inner surface.
 10. A counter torque connectorapparatus in accordance with claim 9 wherein said ballnose and ferruleend fitting protrusions are involute splines.
 11. A counter torqueconnector apparatus in accordance with claim 9 wherein said ballnoseprotrusions extend away from said male connector component and form ahexagonal shape and said ferrule end fitting protrusions form ahexagonal opening for receiving said ballnose protrusion hexagonalshape.
 12. A counter torque connector apparatus in accordance with claim9 wherein said ballnose protrusions extend away from said male connectorcomponent and form a square shape and said ferrule end fittingprotrusions form a square opening for receiving said ballnose protrusionsquare shape.